148 lines
2.8 KiB
C
148 lines
2.8 KiB
C
/*
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* Copyright (C) 2000 David J. Mckay (david.mckay@st.com)
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*
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* May be copied or modified under the terms of the GNU General Public
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* License. See linux/COPYING for more information.
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*
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* Looks after interrupts on the HARP board.
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*
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* Bases on the IPR irq system
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*/
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#include <linux/init.h>
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#include <linux/irq.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/harp/harp.h>
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#define NUM_EXTERNAL_IRQS 16
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// Early versions of the STB1 Overdrive required this nasty frig
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//#define INVERT_INTMASK_WRITES
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static void enable_harp_irq(unsigned int irq);
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static void disable_harp_irq(unsigned int irq);
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/* shutdown is same as "disable" */
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#define shutdown_harp_irq disable_harp_irq
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static void mask_and_ack_harp(unsigned int);
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static void end_harp_irq(unsigned int irq);
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static unsigned int startup_harp_irq(unsigned int irq)
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{
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enable_harp_irq(irq);
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return 0; /* never anything pending */
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}
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static struct hw_interrupt_type harp_irq_type = {
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.typename = "Harp-IRQ",
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.startup = startup_harp_irq,
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.shutdown = shutdown_harp_irq,
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.enable = enable_harp_irq,
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.disable = disable_harp_irq,
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.ack = mask_and_ack_harp,
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.end = end_harp_irq
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};
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static void disable_harp_irq(unsigned int irq)
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{
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unsigned val, flags;
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unsigned maskReg;
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unsigned mask;
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int pri;
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if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
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return;
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pri = 15 - irq;
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if (pri < 8) {
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maskReg = EPLD_INTMASK0;
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} else {
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maskReg = EPLD_INTMASK1;
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pri -= 8;
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}
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local_irq_save(flags);
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mask = ctrl_inl(maskReg);
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mask &= (~(1 << pri));
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#if defined(INVERT_INTMASK_WRITES)
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mask ^= 0xff;
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#endif
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ctrl_outl(mask, maskReg);
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local_irq_restore(flags);
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}
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static void enable_harp_irq(unsigned int irq)
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{
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unsigned flags;
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unsigned maskReg;
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unsigned mask;
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int pri;
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if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
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return;
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pri = 15 - irq;
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if (pri < 8) {
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maskReg = EPLD_INTMASK0;
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} else {
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maskReg = EPLD_INTMASK1;
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pri -= 8;
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}
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local_irq_save(flags);
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mask = ctrl_inl(maskReg);
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mask |= (1 << pri);
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#if defined(INVERT_INTMASK_WRITES)
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mask ^= 0xff;
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#endif
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ctrl_outl(mask, maskReg);
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local_irq_restore(flags);
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}
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/* This functions sets the desired irq handler to be an overdrive type */
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static void __init make_harp_irq(unsigned int irq)
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{
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disable_irq_nosync(irq);
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irq_desc[irq].chip = &harp_irq_type;
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disable_harp_irq(irq);
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}
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static void mask_and_ack_harp(unsigned int irq)
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{
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disable_harp_irq(irq);
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}
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static void end_harp_irq(unsigned int irq)
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{
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enable_harp_irq(irq);
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}
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void __init init_harp_irq(void)
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{
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int i;
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#if !defined(INVERT_INTMASK_WRITES)
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// On the harp these are set to enable an interrupt
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ctrl_outl(0x00, EPLD_INTMASK0);
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ctrl_outl(0x00, EPLD_INTMASK1);
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#else
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// On the Overdrive the data is inverted before being stored in the reg
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ctrl_outl(0xff, EPLD_INTMASK0);
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ctrl_outl(0xff, EPLD_INTMASK1);
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#endif
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for (i = 0; i < NUM_EXTERNAL_IRQS; i++) {
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make_harp_irq(i);
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}
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}
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